The present invention relates to toothbrushes and more particularly to the configurations of the bristle, head and handle portions thereof.
Most hand operated toothbrushes are crafted with the brush head substantially aligned with the handle, in a generally I-shaped configuration. Many years ago, the dental profession generally did not know as much about the treatment of gum disease as it knew about treating tooth decay. At the time, the I-shaped toothbrush was deemed to be adquate for preventing or reducing tooth decay. This brush was designed to facilitate the movement of the brushhead horizontally over the teeth with little or no wrist involvement. However, it was discovered that this brushing pattern tended to force food and debris between the teeth and/or to cause gum erosion. In lieu of changing the conventional I-shaped brush design, it was recommended that the user manipulate the brush head in a generally rotary fashion with ample wrist movement. For many users, however, it is difficult to accomplish effective rotary movements with an I-shaped toothbrush, especially on the inner surfaces of the teeth and particularly for children. Furthermore, it is believed that the I configuration permits the user to apply excessive force, thereby causing abrasion of the teeth and gums. In addition, effective brushing with an I-shaped brush can become tedious and time consuming.
Over the past century, several toothbrushes were designed with the brush head disposed perpendicularly to the long axis of the head to form a T-shaped configuration. U.S. Pat. Nos. Des. 77,115, Des. 175,894 and 1,118,156 illustrate such T-shaped toothbrushes. These brushes were, in theory, conducive to relatively simple and gentle up-and-down brush strokes that would be easy for children to learn and that would effectively remove plaque and other deposits from the interproximal surfaces between the teeth, as well as from the areas of the teeth closest to the gums. In reality, however, there were several problems associated with the T-shaped toothbrush. Some of the brush heads were too wide to reach the inner surfaces of the lower front teeth, where the dental arches are particularly acute. The heads of these early T-shaped brushes and/or the bristle arrays provided thereon were planar concave, or convex. The concave shape impaired the bristles from effectively brushing the inner surfaces of the front teeth. The convex shape impaired the bristles from effectively brushing the outer surfaces of the front teeth, and the planar shape impaired the bristles from effectively brushing either surface of the front teeth. In addition, the straight handle and neck configuration on many of the old T-shaped toothbrushes forced the user to frequently adjust the angle at which the brush was held in the mouth to avoid hitting the chin and other parts of the face during brushing. Furthermore, many of the brush handles were formed with relatively wide flat surfaces, thereby impeding the user's ability to turn the brush in his or her hand. Finally, many of the handles were too short to facilitate brushing of the tongue, the roof of the mouth and the gums behind the last molar teeth. The importance of brushing these toothless areas of the mouth has received some attention relatively recently as knowledge of diseases of the oral cavity has increased. Thus, while the T-shaped toothbrush was, at least in principle, superior in many respects to the I-shaped brush, the foregoing drawbacks, it is believed, virtually eliminated the T-shape from the marketplace.